1. Field of the Invention
This invention relates to a body assembled from at least two component bodies, for example from profiled section rails, having connecting profiled rails which are arranged between the two component bodies and -- considered in cross-section -- comprise two end thickenings which are pushed with clearance into undercut grooves of the component bodies, having a cavity enclosed between the component bodies and filled with a filling composition which exerts an expansion pressure, whereby the connecting profiled rails are subjected to tension stress, and having abutment faces on the end thickenings which extend substantially perpendicularly of the direction of tension and are intended to abut on the groove undercuttings.
Such composed bodies are used especially for frames of doors and windows. The two component bodies here consist of metal profiled rails; the connecting profiled rails consist of insulating material.
2. Description of the Prior Art
Normally as filling composition a liquid initial product is used which can be caused to foam up by activation, generates an expansion pressure and solidifies. Such an assembled body is a stable structure and has the advantage that the two metal profiled rails are extraordinarily well insulated from one another.
A frequently utilized and known profile form for the connecting profiled rails consists of a stem part having retaining flanges angled off at right angles to one side at its two ends. This profile is called U-profile. A modified form is the E-profile where a nose is also provided in the middle of the stem part. The retaining flanges have stop faces extending perpendicularly of the direction of tension, which are intended to abut on the undercuttings of the grooves.
When such profiled forms are used for the connecting profiled rails however the problem explained below occurs:- The insulating material, preferably hard synthetic plastics material, has a high tensile strength but a low bending strength. If the connecting profiled rail is loaded for example by the glazing pressure, then the stem part does not tear but the retaining flanges bend open and slip out of the undercut grooves of the component bodies. Even before they slip out, a variation of spacing of the component bodies and thus as undesired variation of dimension of the assembled body occur.
A sharp-edged formation of the channels on the connecting profiled rails and of the metal edges engaging therein on the groove neck of the component bodies provides no remedy, because then a notch effect occurs and the connecting profiled rails break long before the tensile strength limit is reached.
Therefore attempts have been made to solve the described problem by the use of connecting profiled rails with double-T-profile. The fundamental idea here is that bending open by simultaneous loading of both flanges on each end of the stem part can be avoided. One disadvantage of this profile form however is a large space requirement for the profile webs on the component bodies which grasp on both sides round the ends of the connecting profiled rails, which requirement leads to difficulties in the frequently narrow window profiles. It is a further disadvantage that with the profile webs on the component bodies surrounding the undercut grooves, relatively large metal surfaces stand at a short distance opposite to one another, whereby the thermal insulation is impaired.
It is a third disadvantage that the expansion pressure of the foaming filling composition acting in the cavity presses the profiled rails outwards, so that only the outer retaining flanges abut fully while the inner ones merely rest on the outermost end and the force distribution is not symmetrical as desired. This again, according to the size of the clearance which the retaining flanges of the connecting profiled rails have in the undercut grooves, can lead to the occurrence of tilting forces and thus to an oblique position of the connecting profiled rails. This results in undesired lateral stagger of the component bodies.